Have you ever been about to take a big bite of your triple chocolate fudge cake when someone leaned over and said "you better watch your cholesterol"? That's happening to all of us more frequently. According to The American Heart Association, high levels of cholesterol are a risk factor for coronary heart disease, the nation's number one killer. Over 100 million Americans have cholesterol levels that exceed the recommended total and 20 percent of Americans have levels that are considered high [ref].

What we don't often hear is the important fact that some cholesterol is vital to human life. In this article, we will take a look at cholesterol, both why it is needed for normal human--and animal--functions and why at high levels and in many individuals, it can be deadly. We'll also describe what contributes to and the treatments for high cholesterol levels so that you can take steps to limit your health risks. But first, let's answer an important question: "What is cholesterol?"